I have a tekin r-1 and a sensorless 13.5 and I would like to know if I will have issues if I switch to one cell lipo. Thanks in advance for the replies

You won't like how it pulls out from a stop if does at all.

I Did A Motor Change One Day At The Track And I Forgot To Hook Up The Sensor Wire And When I Hit The Throttle Some Times The Car Would Jerk Backwards Before It Would Go Foward And Even Once It Started To Go Foward If I Got Out Of The Throttle And Got Back In It It Would Still Act Really Jerky

If it works for you in 4 cell it should act the same with single cell.